Telephone-exchange.



H. P. CLAUSEN.

TELEPHONE EXCHANGE.

APPLICATION FILED APR. 12. 1911.

1 352399. Patented Jan. 8,1918.

/n ven/ok: Henry R [Val/sen UNITED STATES PATENT oEE oE.

HENRY ROLAUSEN, OF MOUNT VERNON, NEW YORK, ASSIGNOR TO WESTERN ELECTRICCOMPANY, INCORPORATED, OF NEW YORK, N. Y A CORPORATION OF NEW YORK.

TELEPHONE-EXCHANGE.

Specification of Letters Patent.

Patented Jan. 8, 1918.

Application filed April 12, 1917. Serial No. 161,608.

To all whom it may 007106171.

Be it known that I, HENRY P. (known, a citizen of the United States,residing at Mount Vernon, in the county of Westchester and State of NewYork, have invented certain new and useful Improvements in TelephoneSystems, of which the following is a full, clear, concise, and exactdescription.

This invention relates to telephone systems, and more particularly tosuch systems in which a plurality of subscribers stations are connectedto the same line circuit.

In telephone systems of this type heretofore used there is no means bywhich an operator at a central ofiice may readily determine which of theplurality 0; stations connected with the line has ini iated a call. Thepresent invention provides a simple system in which a. very small amountof apparatus is required for enabling the operator to determine which ofa plurality of stations on the line has initiated a call.

In accordance with the feature of this invention, a telephone linecircuit, to which there are connected a plurality of subscribersstations is equipped with a single tuned vibrating reeds, which areselectively responsive to the vibration of similarly tuned reeds locatedat the various stations and set in motion when a call is initiated. Atthe central oflice, there are line signals controlled by the tuned reedsthereat.

This invention is illustrated in the accompanying drawing, whereinconductors 5 and 6 constitute a line circuit to which is connected aplurality of subscribers stations A, B, G and D. This line circuitterminates at a central office in a plurality of jacks 10, 11, 12 and13. Connected with the line conductor 6 is the winding of anelectromagnet 7 which acts upon four tuned reeds 20, 21, 22 and 23. Eachof these reeds is of a different length and is, therefore, tuned torespond to a different frequency of vibration. At the stations there arelocated reeds 30, 31, 32 and 33, one being at each station. Each ofthese reeds is of a different length and therefore has a different rateof vibration. The reed at each station is adapted to be set in'vibrationwhen the receiver thereat is removed from the switchhook to initiate acall. The vibrating reeds at the subscribers stations may, therefore, beconsidered as generators of currents of difl'erent frequencies Each ofthe reeds controlled by electromagnet 7, when responding to the properfrequency, closes an energizing circuit for a relay controlled thereby,for example, reed 20 controls relay 4C0; reed 21 controls relay 41; reed22 controls relay 42; and reed 23 controls relay 4.3. These relaysrespectively control line signaling lamps 50, 51, 52 and 53 associatedrespectively with the jacks 10, 11, 12 and 13.

Referring now to the operation of the sys tem disclosed in the drawing,it will be assumed that the subscriber at station A initiates a call. Inso doing, the removal of the receiver from the switchhook sets reed 30in vibration, thereby causing it to intermittently close a contact incircuit with the winding of electromagnet 7. This circuit may be tracedfrom battery through the winding of electromagnet 7, contact of cutoffrelay 14, line conductor 6, and the vibrating reed 30 to ground.Impulses of cur rent are thereupon transmitted through the Winding ofelectromagnet 7 at a rate depending upon the rate of vibration of thisreed. Reed 20, controlled by electromagnet 7, is set in vibration as aresult of the passage of these current impulses governed by reed 30 atstation A through the Winding of electromagnet 7, thereby causing theoperation of relay 40, over a circuit from battery through the windingof relay 40, normal contact thereof, and reed 20 to ground. Relay 10, inoperating, closes a locking circuit for itself from battery through thewinding of left-hand normal contact of relay 40, and the contact of jack10 to ground. Relay 40, in operating, also causes the line lamp 30 to belighted. The operator, in responding tothe lighted condition of thisline lamp, inserts a plug 15 into jack 10, thereby opening the lampcircuit of relay 40 and efli'acing the line lamp, and also causing theoperation of cut-off relay 1.4, thereby disconnecting the'electromagnet7 from the line circuit.

In a similar manner, reed 21 responds to the vibration of the reed 31when station B initiates a call and as a result the line lamp 51 islighted. In a similar manner, line lamp 52-or 53' maybe lighted.

From the above description it will be evident that this inventionprovides a very simple system in which the operator is enabled todetermine which of a plurality of stations connected with the linecircuit has initiated a call. In thus being able to determine which of aplurality of stations has initiateda call the operator may, without anyfurther action, make the proper notation for charging the call to the.proper Sta,- tion. In systems heretofore used it has been necessary,when a station on a. party line has initiated'a'call, for the operatorto inquire of the calling subscriber the number of his station. It willbe seen, therefore, that the system embodying the present invention is adecided improvement over systems. heretofore employed.

What is claimed is:

1. A telephone system comprising a telephone line terminating at acentral office, a plurality of subscribers stations connected with thetelephone line, means at each station for generating currents ofdifferent freuencies, an electromagnetic device selectively responsiveto the currents so gener ated, and a signaling device at the centralofiice individual to each station and selectively controlled by saiddevice.

2. A telephone system comprising a telephone line terminating at acentral oflice, a plurality of subscribers stations connected with-thetelephone line, means comprising a tuned reed at each station forgenerating currents of different frequencies, an electromagnetic devlceat the central oflice selectivelyresponsive :to the currents sogenerated, and a signaling device at the central oflice individual toeach station and selectively controlled by said device.

3. A telephone system comprising a telephone line terminating at acentral ofiice, a plurality of subscribers stations connected with thetelephone line, means including a tuned reed at each station forgenerating currents of different frequencies, an electromagnetic deviceincluding a plurality of tuned reeds selectively responsive to thecurrents generated at the stations, and a signaling device at thecentral office individual to each station and selectively controlled bysaid device.

4. A telephone system comprising a telephone line terminating at acentral office, a plurality of subscribers stations connected with thetelephone line, means at each station including a tuned reed set inmotion upon the removal of the receiver-from the switchhook forgenerating currents of different frequencies, an electromagnetic'deviceincluding a plurality of tuned reeds selectively responsive to thecurrents so generated and a signaling device at the central ofiiceindividual to each station and selec tively controlled by said device.

5'. A telephone system comprising a telephone line terminating at acentral office. a pluralityof subscribers stations connected with thetelephone line, means at each station including a tuned reed set inmotion upon the removal of the receiver from the switchhook, forgenerating currents of different frequencies, an electromagnetic deviceincluding a plurality of tuned reeds selectively responsive to the.currents so generated, a signaling device at the central oiiiceindividual to each station, and a relay controlling each signalingdevice and selectively controlled by said electromagnetic device.

. 6. A telephone system comprising a telephone line terminating at acentral office, a jplurality of subscribers stations connected. with thetelephone line, means at each station including a tuned reed set inmotion upon the removal of the receiver from the switchhook forgeneratingcurrents of different frequencies, an electromagnetic deviceincluding a plurality of tuned reeds selectively responsive to thecurrents so generated, a signaling device at the central officeindividual to each station, arelay controlling each signaling device andselectively energizedunder control of said electromagnetic device, and alocking circuit for each relay completed upon energization thereof.

71A telephone system comprising a telephoneline terminating at. acentral office in a plurality of terminals, a plurality of subscribersstations connected with the telephone line, means at each stationincluding a tuned reedse-t in motion upon the removal of the receiverfrom the switchhook for gen erating currents of different frequencies,an electromagnetic device including a plurality oftuned reedsselectively responsiveto the currents so generated, a signaling deviceassociated with each terminal and individual to each station, a relaycontrolling each sig naling device and selectively energized undercontrol of said electromagnetic device,

a locking circuit for each relay completed cuit of the actuated relay.

- In witness whereof, I hereunto subscribe my name this 10th day ofApril A. D., 1917.

.IIHENRY P. CLAUSEN.

egg-it s of this patent maybe obtained for five cents each, byaddressing the vcommiss ioner o1. 'Batents, 1 ic hinstomD-G. Y

